Allergic diseases continue to pose a significant public health burden in modernized societies. Although the etiology of allergic diseases is unknown, they are thought to develop as a result of aberrant Th2 immune responses in genetically susceptible individuals. Despite this recognition, the factors driving Th2-mediated immune responses have remained elusive. Our preliminary data suggests the novel paradigm that allergen exposure induces epithelial cell injury which results in the release of an epithelial-derived factor, trefoil factor 2. Tff2, in turn induces the release of the